Device for Wrapping Products

ABSTRACT

A system for wrapping sets of products with a stretch film has a first conveyor belt with the incoming products, a second outgoing conveyor belt with the products wrapped in the stretch film, and one or more devices for wrapping the products with a stretch film, each device being provided with a handling robot with a handling end, to which a wrapping and gripping assembly is fixed that includes a wrapping head for wrapping the stretch film and gripping elements for gripping and rotating the products while the stretch film is wrapped.

TECHNICAL FIELD OF THE INVENTION

The present invention refers to a device for wrapping products, such asbottles, containers, also those made of metal, usually with cylindricalor prismatic shape, etcetera, which are grouped together in two or moreproducts according to different types. One example includes loads of sixplastic bottles arranged in two three-bottle rows, so as to allow aneasier transport thereof.

STATE OF THE ART

In the systems according to the state of the art, the grouped productsare moved along a conveyor belt where they are wrapped with a sheet ofheat-shrinking plastic material in a manner such that the ends of thesheet are superimposed, then the products thus wrapped are subjected toa heating step.

The plastic material sheet, due to the heat-shrinking characteristics,is joined at the end, is shrunk, adhering to the products and defining astable package.

This mode of packaging has different problems: it is necessary toprovide for a heating oven, with consequent complication and increasedenergy cost, increased cost of the heat-shrinking plastic material,impossibility for certain types of containers and contained product toexceed certain temperature levels, and hence impossibility toeffectively carry out the heat-shrinkable action on the plasticmaterial.

It has therefore been proposed to substitute the heat-shrinkable plasticmaterial with a stretch film.

In the German patent application No. DE3910823, an apparatus isillustrated for packaging a certain number of bottles or similarproducts with a stretch film, which allows a wrapping without a tray orcardboard support for the products.

The products which arrive from a conveyor belt are retained by means ofguide rods, which are engaged around the neck of the products and in atleast one recess in the bottom. The wrapping station is designed so thatthe products, together with the guide rods, are wrapped with the stretchfilm from a coil with a horizontal wrapping axis that rotates around theproducts themselves.

Also the European patent No. EP2470438B1 illustrates a similar packagingsystem, in which an assembly of bottles is pressed by two jaws to form acompact set and a film coil rotates around the group of bottles and onthe gripping jaws.

These wrapping systems have different drawbacks, including aconsiderable structural complication and a considerable bulk due to theneed to rotate the coil around the group of products, and there is alsothe need to stop the products on the conveyor belt due to the timenecessary for the wrapping step.

In addition, it is impossible to continuously operate due to the machinestop times required for substituting the wrapping film coil or foreliminating possible jamming or possible malfunctions tied to the coilor film.

SUMMARY OF THE INVENTION

One object of the present invention is to improve the state of the art.

Another object of the present invention is to increase the productivityof the product wrapping devices, making their packaging quicker and morecontinuous.

Still another object of the present invention is to propose a device forwrapping products provided with a wrapping and gripping assembly thatallows decreasing the device stop time due to depletion or jamming ofthe wrapping film.

A further object of the present invention is to propose a device forwrapping products which allows a change of the coil in an automatic andpractical manner, reducing the tooling and relative device stop times,in the scope of a simple, rational solution, with easy and effective useand with limited costs.

In accordance with one aspect of the present invention, a device isprovided for wrapping sets of products according to the presentapplication.

In accordance with another aspect of the present invention, a system isprovided for wrapping sets of products according to the presentapplication.

The present application refers to preferred and advantageous embodimentsof the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristics and advantages of the present invention will bemore evident from the detailed description of a preferred but notexclusive embodiment of a device for wrapping products, illustrated as anon-limiting example in the enclosed drawing tables in which:

FIG. 1 is an overall perspective view of a system provided with severaldevices for wrapping sets of products according to the presentinvention;

FIG. 2 is an enlarged perspective view of a device for wrapping sets ofproducts pursuant to FIG. 1;

FIG. 3 is an enlarged perspective view of a detail of the device forwrapping sets of products pursuant to the preceding figures; and

FIG. 4 is another enlarged perspective view of the detail pursuant toFIG. 3; and FIGS. 5 to 12 illustrate a sequence of wrapping a set ofproducts, achieved with a device according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

With reference to FIG. 1, reference number 10 schematically indicates asystem provided with three devices 1 for wrapping sets of products 2such as bottles, packs, boxes and the like.

In the following description, a system 10 will be illustrated with threedevices 1 for wrapping a set of six bottles with a stretch film;nevertheless, it must be considered that any number of devices 1 can beused, starting from one device, and that in addition the products to bewrapped can be of any type or number.

The system 10 comprises a first conveyor belt 3, on which the products 2to be wrapped with the stretch film arrive, already grouped together; inthis embodiment, there are six bottles grouped in two rows of three.

A second conveyor belt 4 is also present, on which the products 2wrapped in the stretch film are deposited so as to form packages 5; fromthis second conveyor belt 4, the packages 5 are sent to possiblesubsequent treatment and/or palletization stations which are notdescribed further herein since they are not part of the presentinvention.

It must be observed that the advancing direction of the first conveyorbelt 3 and second conveyor belt 4 can be any direction; in addition, inthe illustrated embodiment, the two conveyor belts 3 and 4 are parallelto each other, but it must be considered that the aforesaid conveyorbelts can have any mutual arrangement, i.e. for example, perpendicular,or oblique, thus making the system 10 very flexible as an installationpossibility. In addition, if a sufficient number of devices 1 isprovided, all the operations for wrapping the products 2 can be carriedout on a single belt.

Each wrapping device 1 essentially comprises a handling robot 6,provided with a handling end 7; such robot 6 in the embodimentillustrated in the figures is of anthropomorphous type, but it could beof another type, such as Cartesian or polar with at least three or fouraxes. Also provided are a wrapping head 8, fixed to the handling end 7of the robot 6, and gripping means 9 for gripping the products 2, thesetoo fixed to the handling end 7 of the robot 6.

FIGS. 3 and 4 illustrate the wrapping head 8 in detail.

The wrapping head 8 is provided with a coil 11 of stretch film 12 forwrapping the products 2 and comprises a box-shaped body 13 that containsmeans for actuating in rotation the coil 11, means for pre-stretching 14the wrapping film, means for applying 15 the same film on the products 2and means for cutting 16 the film to complete the application of thefilm on the products, these means not described in more detail hereinsince they are not the object of the present invention.

The gripping means 9 are fixed to the handling end 7 of the robot 6 bymeans of brackets 17; in turn, the brackets 17 are connected to thebox-shaped body 13 of the wrapping head 8, so as to form with theaforesaid head 8 a wrapping and gripping assembly 20 that can beautomatically substituted by the robot 6.

In FIG. 1, it can in fact be observed that next to each robot 6, atleast one wrapping and gripping assembly 20 is positioned which iswaiting to be picked up by the robot 6. When the wrapping head 8receives a signal that the coil 11 is terminating the stretch film 12,the robot 6 completes the products 2 wrapping cycle that is underway andrests the assembly 20 in a free parking zone.

The robot 6 comprises, on the end 7, attachment means 21 which areprovided for hooking or unhooking on command to/from correspondingfixing means, e.g. a shank 22, positioned on the assembly 20.

Therefore, by means of the attachment means 21, the robot 6 unhooks theassembly 20 with the depleted coil 11 and immediately picks up anotherassembly 20 with the full coil 11 of stretch film 12.

It is therefore clear that the time for changing the wrapping andgripping assembly 20 is much less than that for substituting the coil 11and inserting the film 12 in the pre-stretching means 14.

On the other hand, when the assembly 20 with the depleted coil 11 hasbeen parked in the parking zone, an operator has all the time availablefor changing the depleted coil with a full coil and for inserting thefilm 12 in the pre-stretching means 14, since the wrapping device 1 isalready operational, having picked up an assembly 20 with a new coil 11full of stretch film 12.

The gripping means 9 comprise two jaws 18 provided with rod-likeelements 19 capable of compacting together the products 2; the rod-likeelements 19 also have a shape and a structure that allows them to beextracted when they are situated inside the wrapping formed by the film12 in the package 5.

More in detail, the rod-like elements 19 are suitably shaped based onthe particular shape of the products 2 to be grasped, so as to correctlycompact them and retain them without risking deformation, squashing orother damage.

If desired, the rod-like elements 19 can be substituted by the jaws 18as a function of the type of product to be treated, e.g. bricks,half-liter or 1.5 liter bottles, boxes, etcetera. For such purpose,means can be provided for unhooking or disengaging (such as screw means,bayonet means, snap means, etcetera) the rod-like elements 19 from thejaws 18, e.g. quick unhooking or disengagement means.

As an alternative or in addition thereto, the device can be providedwith a control unit having means for storing or setting the size of theproducts and, more particularly, means for associating (e.g. by means ofsuitable software) each product with a respective treatment sequence orscheme; the control unit is also set to drive the device or better yetthe jaws 18, in a manner such to suitably compact the products as afunction of the actual size of the products themselves, i.e. so as tocompact each product according to the respective treatment sequence orscheme, which is, if desired, different from the treatment sequence orscheme of other products. In substance, once the type of product to betreated is established or set in the control unit, the control unitwould drive the jaws 18 in a manner such to compact the products by thedesired amount, suitably pushing the jaws 18 or making them complete apredetermined travel thereof.

The two jaws 18 are opened or closed in opposite manner, according to asubstantially horizontal direction “X”, by means of the drive means 23.

The drive means 23 can be made in different ways. In the embodimentillustrated in FIGS. 3 and 4, the drive means 23 comprise substantiallyhorizontal guides 24 and toothed belts 25 driven by an electric motor26. The two jaws 18 are slidable on the substantially horizontal guides24 and are fixed to a branch of each toothed belt 25, which determinethe opposed opening or closing movement of the jaws 18.

The gripping means 9 also comprise rotation means 27 which allow therotation of the products 2 when they are gripped by the jaws 18.

Also, the rotation means 27 can be made in different ways, and in theembodiment illustrated in the figures they comprise two gearmotors 28that rotate around the axis “X” in a concurrent and synchronized way inspeed and phase, due to an electrical axis between the two motors, i.e.by means of suitable sensors and electric adjustment means of themotors.

It is thus possible to carry out the rotation of the products 2 grippedby the jaws 18, wrapping the stretch film 12 around the set of products2.

In particular, the shaped rod-like elements 19 are adapted to dischargethe tension due to the wrapping of the film 12 around the products 2. Insuch a manner, the latter do not show any squashing, deformation orother damage that would otherwise be caused by the tightening of thefilm 12, during the wrapping step.

It must be observed that, due to the robot 6, the products 2 are movedfrom the incoming first conveyor belt 3 to the second outgoing conveyorbelt 4, while the operation of wrapping the stretch film 12 on theproducts 2 themselves takes place.

An advantage is therefore obtained with regard to time, as well as thepossibility to place the two belts 3 and 4 with the maximum arrangementfreedom.

FIGS. 5 to 12 illustrate a wrapping sequence of a group of products 2.

In FIG. 5, the jaws 18 are observed arranged above a set of products 2.It must be noted that the conveyor belt 3 does not have to stop sincethe robot 6 is capable of being adapted to the translation speed of theproducts 2 on the belt 3; in FIG. 6, the jaws 18 in open positionapproach each other, being lowered on the set of products 2 and in FIG.7 the jaws 18 are closed, compacting the set of products 2, then theapplication means 15 apply the free flap of the stretch film 12 on theset of products 2.

In FIG. 8, the robot 6 has lifted the assembly 20 to allow the rotationof the set of products 2 and starts the rotation of the set of productsaround the axis “X” which allows wrapping the stretch film 12 around theset of products 2; in FIGS. 9 and 10, the rotation of the set ofproducts 2 continues, while the robot 6 moves the set of products 2towards the second conveyor belt 4.

In FIG. 11, the wrapping of the stretch film 12 around the set ofproducts 2 has been completed and the cutting means 16 cut the film 12,completing the packaging of the products.

Then, the robot 6 lowers the set of products 2 on the second conveyorbelt 4; also in this case, it must be observed that the conveyor belt 4can be moving since the robot 6 is capable of being adapted to thetranslation speed of the belt 4.

In FIG. 12, the jaws 18 are opened, the rod-like elements 19 which aresituated inside the wrapping formed by the film 12 can be removed andthe package 5 of products 2 can be released on the outgoing conveyorbelt 4; the robot 6 can return towards the first conveyor belt 3 inorder to start a new wrapping operation.

The described device attains the pre-established objects in the scope ofa solution with reduced bulk and a high productivity due to this newwrapping type.

Indeed, it must be observed that it is possible to have multiple robots6 on same conveyor line, thus increasing the number of treated productsin accordance with requirements.

In addition, the presence of a sufficient number of robots 6 allows thealready-described possibility to carry out all the operations forwrapping the products 2 on a single belt. Each robot 6 picks up a set ofproducts 2 from one position on the single belt in order to carry outthe wrapping operations thereon; once such operations have terminated,the robot once again deposits the set of products 2 on the single beltin the same position as the initial pick up, or alternatively at anotherfree position.

The invention thus conceived is susceptible of numerous modificationsand variants, all falling within the scope of the inventive concept.

In addition, all details can be substituted by other technicallyequivalent elements. In practice, the materials used, as well as thecontingent shapes and sizes, can be of any type in accordance with therequirements, without departing from the protective scope of thefollowing claims.

1. A device for wrapping sets of products through a stretch film,comprising a wrapping and gripping assembly which includes a wrappinghead for wrapping said stretch film and gripping means for gripping androtation of said sets of products according to a substantiallyhorizontal direction (X), further comprising a handling robot, providedwith a handling end, to which said wrapping and gripping assembly isfixed.
 2. The device according to claim 1, wherein said handling robotcomprises attachment means placed on said handling end and said wrappingand gripping assembly comprises fixing means, said attachment meansbeing provided for hooking or unhooking on command to said fixing means.3. The device according to claim 1, wherein said wrapping head isprovided with a coil of stretch film for wrapping the products andcomprises a box-shaped body which contains means for actuating inrotation the coil, means for pre-stretching the wrapping film, means forapplying the same film on the sets of products and means for cutting thefilm to complete the application of the film on the sets of products. 4.The device according to claim 1, wherein said gripping means comprisedrive means to open or close said gripping means according to saidsubstantially horizontal direction (X) and to compact the sets ofproducts.
 5. The device according to claim 1, wherein said grippingmeans comprise two jaws able to take the set of products.
 6. The deviceaccording to claim 5, wherein said jaws comprise rodlike elements havinga shape and a structure that allows them to be extract from the insideof the wrapping made from the film on the set of products.
 7. The deviceaccording to claim 6, wherein said rod-like elements are suitably shapedbased on the particular shape of the products to be grasped, and areadapted to discharge the tension due to the wrapping of said film aroundthe products, so as to preserve the products from any squashing,deformation or other damage during the wrapping step.
 8. The deviceaccording to claim 1, wherein said gripping means comprise rotationmeans for the rotation of the products when they have been gripped bysaid gripping means.
 9. The device according to claim 8, wherein saidrotation means comprise two gearmotors in rotation around said axis (X)in a concurrent and synchronized way in speed and phase, thanks to anelectric axis between the two motors, namely through appropriate sensorsand electric adjustment means of the motors.
 10. The device according toclaim 5, comprising hooking or unhooking means, optionally quick, ofrod-like elements from said jaws and/or a control unit having means forconnecting each product to a respective scheme or treatment sequence,said control unit being in charge of steering said jaws so as to compacteach product according to its respective scheme or treatment sequence.11. A system for wrapping sets of products with a stretch filmcomprising one or more devices 04 according to claim
 1. 12. The systemaccording to claim 11, comprising at least a first conveyor belt withthe incoming products and at least a second conveyor belt with theoutgoing products wrapped in the stretch film.